Intracoronary Beta‐Radiation Therapy for In‐stent Restenosis: Long‐Term Success Rate and Prediction of Failure

OBJECTIVE: The following retrospective observational study assesses the long-term results of intracoronary beta-radiation therapy for patients with in-stent restenosis. BACKGROUND: Beta-radiation has been used to treat patients with coronary in-stent restenosis. However, long-term clinical success using this technique has not at this time been established. METHODS: Two-hundred and thirteen consecutive patients received intracoronary brachytherapy (noncentered beta-emitter, Novoste BetaCath) for in-stent restenosis and were followed up over a period of 39.1 +/- 18.4 months. The combined end-point was defined as a major adverse clinical event (MACE)and comprised mortality, acute myocardial infarction, or target vessel revascularization (TVR). RESULTS: MACE occurred in 110 patients (51.6%): death in 27 patients (12.7%), acute myocardial infarction in 8 patients (3.8%), TVR in 90 patients (42.3%). TVR comprised percutaneous coronary reinterventions in 76 patients (35.7%) and coronary bypass surgery in 24 patients (11.3%). Secondary end-point was determined as target vessel failure and occurred in 93 patients (43.7%). Of note, the frequency of at least two previous target lesion interventions as well as impairment of left ventricular function was associated with reduced success rate, whereas other clinical parameters did not indicate outcome after treatment with intracoronary radiation therapy. CONCLUSION: During the mean, a period of 3 years, more than half of the patients receiving intracoronary radiation therapy reached primary end-point, representing, in the main, TVR. During this period a mortality rate of nearly 13% was documented. These results signify a delayed, though continued, restenotic process after index procedure.